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I currently pay and have been paying for the 100mbs option of Xfinity internet. I noticed a problem when I couldn't even stream youtube videos at 360p. Pictures load like when I was on a 14k modem. Looking at various download speed tests I am getting sub 1mbs , rarely peaking to ~20mbs then immediately back down to sub 1mbs.
This problem has persisted throughout the years I have lived here with Comcast as my provider. It has only gotten worse with time. I pay too much to recieve so little. I have done the song and dance of reset modem etc, and had someone come to take a look at it some many months ago from comcast, he saw a problem and had someone else come out assist him. It was better for a short time and is now in terrible shape and shows no signs of improving. This problem has persisted through different computers/os/modems/ coax cables etc. If there was something to change on my end, I have.
Researching the problems and looking at the symptoms and modem error codes:
Arris SBG6700-AC is my modem
SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing
Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out
Started Unicast Maintenance Ranging - No Response received - T3 time-out
No Ranging Response received - T3 time-out
Levels from today:
| Channel | Lock Status | Modulation | Channel ID | Frequency | Power | SNR | Corrected | Uncorrectables |
| 1 | Locked | QAM256 | 21 | 729000000 Hz | -11.4 dBmV | 37.8 dB | 2 | 0 |
| 2 | Locked | QAM256 | 17 | 705000000 Hz | -12.1 dBmV | 37.2 dB | 682576 | 2165430 |
| 3 | Locked | QAM256 | 18 | 711000000 Hz | -12.1 dBmV | 37.2 dB | 241786 | 943630 |
| 4 | Locked | QAM256 | 19 | 717000000 Hz | -11.2 dBmV | 37.5 dB | 931 | 0 |
| 5 | Locked | QAM256 | 20 | 723000000 Hz | -11.4 dBmV | 37.5 dB | 6 | 0 |
| 6 | Locked | QAM256 | 22 | 735000000 Hz | -10.1 dBmV | 38.0 dB | 0 | 0 |
| 7 | Locked | QAM256 | 23 | 741000000 Hz | -10.9 dBmV | 37.6 dB | 0 | 0 |
| 8 | Locked | QAM256 | 24 | 747000000 Hz | -10.8 dBmV | 27.5 dB | 2473583 | 1917796 |
| Upstream Bonded Channels | ||||||
|---|---|---|---|---|---|---|
| Channel | Lock Status | US Channel Type | Channel ID | Symbol Rate | Frequency | Power |
| 1 | Locked | ATDMA | 6 | 5120 Ksym/sec | 29400000 Hz | 44.0 dBmV |
| 2 | Locked | ATDMA | 5 | 5120 Ksym/sec | 35800000 Hz | 42.5 dBmV |
| 3 | Locked | ATDMA | 7 | 5120 Ksym/sec | 23000000 Hz | 42.5 dBmV |
another pic of the levels (older)
Everything I see with similar issues points to too many splits.
I decided to go look for myself, maybe I can see a problem. Its a light rain outside. Since I never go on this side of the building I was suprised see the cover thrown to the ground and the wires left dangling in the rain.
Upon investigation here's what I found. If you look at the picture 2 cables come from the pipe down there to supply the building. Then one of said lines goes into a 4way split. From here some apartments have 2cables running into them. Not mine though.
With my apartment (and I am assuming the lables are correct). From what I finger traced. 1 of the two supply cables goes into a 4way split. then from the 1 of the 4 it then goes into an 8way split from there it may be split again. I see a two way split thrown in there.. You can almost see it from the picture. 8 Apartments, with 2 source cables feeding the building. Some apartments are getting half a source cable(like #23 you see there). I am just getting 'badword'ed?
https://imgur.com/a/r1aAz imgur album link
I would like some help/answers/recompense.
Edit: I should add that it is worse at night through early morning when I am typically on the computer. I work nights, come home and game/stream etc. Usually sleep during the day. However, days I'm off-work it seems healthier during the day.
Perhaps it would be best to book a tech to come and sort this one out.
I am not a Comcast Employee.
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I am a fellow customer, volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark the post as best answer!
What @EG said. Your performance is lousy because your signals are lousy. Looks like you are going to need a tech to sort it out. FYI it's fine if those cables get wet, they are designed to be exposed to the elements.
I've asked a Comcast employee to help you. You should expect a reply in this thread. 
Hi Scipio5,
I can help get a tech out to have this taken care of for you. Please send me a private message by clicking on my name, "ComcastChe" then click private message me. In the body of this message please verify your first and last name, street address including city state and zip code, and the account number or phone number associated with your services.
I am an Official Comcast Employee.
Official Employees are from multiple teams within Comcast: Product, Support, Leadership. We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark the post as best answer!
Official Employees are from multiple teams within Comcast: Product, Support, Leadership. We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark the post as best answer!
You're very welcome!
I am an Official Comcast Employee.
Official Employees are from multiple teams within Comcast: Product, Support, Leadership. We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark the post as best answer!
Official Employees are from multiple teams within Comcast: Product, Support, Leadership. We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark the post as best answer!
